基于影响面范围的钢桥面板构造细节应力分析

ANALYSIS ON STRUCTURAL STRESS OF STEEL BRIDGE DECK BASED ON INFLUENCE SCOPE

建立不同横隔板间距的正交异性钢桥面板节段有限元模型,选取顶板与U肋焊缝细节、U肋与横隔板焊缝细节、U肋对接焊缝三种典型疲劳细节,通过改变车轮荷载的位置,得到各细节的应力影响面,根据应力与应力幅大小确定车轮纵向与横向位置的应力影响范围,以及荷载最不利位置,并结合测点的上、中、下三层表面应力分析各个构造细节的局部受力特征。结果表明：车轮荷载位置对顶板与U肋焊缝细节、U肋与横隔板焊缝细节、U肋对接焊缝的纵向影响范围均为2个横隔板间距;顶板与U肋焊缝横向影响范围为900 mm,以受弯为主; U肋与横隔板焊缝处横向影响范围为1 350 mm,存在面内受力; U肋对接焊缝的影响范围为900 mm,以拉压作用为主。

The finite element models of orthotropic steel bridge deck（ OSD） with different spacings between diaphragms were established. Three construction details were adopted including weld joints between deck and U-rib,weld joints between U-rib and diaphragm and U-rib butt welds. Stress influence scopes of different details were obtained by changing the position of wheel load. Stress influence scopes under vertical or transverse locations of the wheel and the most unfavorable position of load were determined based on the stress and stress amplitude. Combined with the stress of the top surface,the mid surface and the bottom surface of the measuring details,the stress characteristics of different construction details were analyzed. The analysis results indicated that the vertical influence scope of the vehicle location to the construction details were two spacings between diaphragms; the weld joints between deck and U-rib were mainly subjected to bending load with the 900 mm of the transverse influence scope; the weld joints between U-rib and diaphragm were partly subjected to in-plane stress with the 1 350 mm of the transverse influence scope; the U-rib butt welds were mainly subjected to tension and compression stress with the 900 mm of the transverse influence scope.